222 ANA 7VMY AND PHYSIOLOGY FOR NURSES 



tions. It is the motor nerve of the muscles of the face. 

 It takes its origin in the pons Varolii and lateral columns 

 of the medulla, and has its deep origin in the floor of the 

 fourth ventricle. Its branches are the tympanic, chorda 

 tympani, posterior auricular, digastric, stylohyoid, tem- 

 porofacial (which subdivides into temporal, malar, infra- 

 orbital), cervicofacial (which subdivides into buccal, su- 

 pramaxillary, and inf ramaxillary ) . The facial communi- 

 cates with the auditory nerve; with Meckel's ganglion by 

 the large petrosal; with the optic ganglion by the small 

 petrosal; with the sympathetic on the middle meningeal 

 by the external petrosal nerve; with the pneumogastric, 

 glossopharyngeal, carotid plexus, auricularis magnus, au- 

 riculotemporal, and with the three divisions of the fifth 

 nerve. The importance of this nerve is apparent from its 

 many communications, and it can readily be seen that in- 

 jury to a part will interfere with the several relations of this 

 nerve structure. 



The eighth, or auditory, is the nerve of hearing. It 

 begins by two roots, arising from the medulla oblongata; 

 it is distributed to the internal ear by two branches the 

 vestibular, to the vestibule, and the cochlear, to the cochlea. 



The ninth, or glossopharyngeal, is a nerve of common 

 sensation, and also the nerve for the special sense of taste. 

 It arises from the medulla oblongata, behind the olivary 

 bodies, the deeper origin being from the floor of the fourth 

 ventricle. This nerve emerges through the jugular fora- 

 men, and presents two enlargements or ganglia the 

 jugular and the petrosal. It is distributed to the muscles 

 of the pharynx, mucous membranes of the pharynx, fauces, 

 tonsils, tongue, and middle ear; for that purpose it gives 

 off the following branches, which are distributed to the 

 various parts indicated by their names: Tympanic, caro- 

 tid, pharyngeal, muscular, tonsillar, and lingual. 



The tenth, the pneumogastric, called the vagus nerve, 



